JP4867079B2 - Quartz polymer plate manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a quartz polymer plate used for various sensors, actuators and the like.
[0002]
[Prior art]
A conventional example will be described with reference to FIGS.
[0003]
As shown in FIG. 13, the quartz crystal plate superposes two quartz plates 1 and 2 and heats them in this state. As a result of the heating, the water present at the contact portion of the two evaporates, whereby an interatomic bond mediated by oxygen atoms is performed in this portion.
[0004]
Gold masks 3 and 4 are respectively provided on the surface of such a polymerized quartz plate, and in this state, dissolution by wet etching is performed simultaneously from both as shown in FIG. By this melting, as shown in FIG. 15, a process of penetrating vertically is performed, whereby a quartz polymer plate 5 that is an individual piece as shown in FIG. 16 is formed. Thereafter, as shown in FIG. 17, the quartz polymer plate 5 is further dissolved on both sides thereof by wet etching, thereby adjusting the resonance frequency.
[0005]
[Problems to be solved by the invention]
The problem in the above conventional example is that the sensitivity of the quartz polymer plate is lowered. That is, this quartz superposition plate is used as a sensor or actuator as described above, and double sensitivity can be obtained by superposing the quartz plates 1 and 2 and inverting their polarization axes. However, as shown in FIG. 17, when the resonance frequency is adjusted, when wet etching is performed, dissolution greatly proceeds inward from the interatomic junction of the crystal plates 1 and 2. Will end up.
[0006]
Since the melted portion is a portion where the upper and lower quartz plates 1 and 2 are not superposed, that is, the superposed area of the upper and lower quartz plates 1 and 2 is reduced. It will fall.
[0007]
Accordingly, the present invention aims to increase the sensitivity of the quartz polymer plate.
[0008]
[Means for Solving the Problems]
In order to achieve this object, the present invention connects at least two quartz plates between atoms, cuts this superposed quartz plate with plasma from one surface side, and then corresponds to the cut surface from one side. Plasma cutting is performed from the other surface side of the superposed crystal plate.
[0009]
That is, when the polymerized quartz plate is cut by plasma from one and the other surface side as described above, the cutting is a physical cutting, so unlike the case of conventional wet etching, The shape change due to the difference in the etching rate of the crystal plane is less likely to occur.
[0010]
In other words, when such plasma cutting from the front and back surfaces is performed, the outer peripheral portion of the polymerized quartz plate has a shape protruding outward, and thus has a shape protruding outward. Then, even if the resonance frequency is adjusted by, for example, dissolving by wet etching, it is only in contact with the top and bottom, and the part protruding outward is slightly cut inward. In such a case, the original bonding area of the upper and lower quartz plates is not reduced, and this can increase the sensitivity.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
According to the first aspect of the present invention, at least two quartz plates are interatomically bonded, the superposed quartz plate is cut by plasma from one surface side, and then corresponds to the cut surface from the one side. A method for producing a crystal polymerized plate that performs plasma cutting from the other surface side of the polymerized crystal plate, wherein the polymerized crystal plate is cut by plasma from one and the other surface side as described above. Since the cutting is a physical cutting, unlike the conventional wet etching, the shape change due to the difference in the etching rate of the crystal plane is less likely to occur.
[0012]
In other words, when plasma cutting is performed from the front and back surfaces, the outer peripheral portion of the polymerized crystal plate has a shape protruding outward, and thus has a shape protruding outward. Then, even if the resonance frequency is adjusted by, for example, dissolving by wet etching, it is only in contact with the top and bottom and the portion protruding outward is slightly cut inward. In this case, the original bonding area of the upper and lower quartz plates is not reduced, and this can increase the sensitivity.
[0013]
Next, according to the second aspect of the present invention, an island-shaped mask is provided in a cut portion on one surface of the polymerized quartz plate, and the periphery of the island-shaped mask reaches another quartz plate that is superposed on this quartz plate. The method for producing a quartz polymer plate according to claim 1, wherein plasma cutting is performed so as to perform plasma cutting from the other surface, and an island-shaped mask is first provided on one cutting portion on the side to be performed first, When plasma cutting is performed in this state, for example, a circular groove is dug on the outer periphery of the island mask.
[0014]
This circular groove reaches the other quartz plate, and when plasma cutting is performed from the other quartz plate in this state, the plasma cutting from the other quartz plate is performed. The tip side, i.e., the bottom part, due to the above will reach a groove that has been excavated, and if this is the case, the upper and lower plasma cutting contact parts will always be in contact with this superposed crystal plate It becomes possible to maintain the state where both protrude outwardly at the portion.
[0015]
Therefore, even in the state where both of them protrude in the same manner as described above, even if dissolution is performed by wet etching, the joint portion is present in a position protruding sufficiently outward, and thus sufficiently Even if dissolution by wet etching, for example, progresses inward from the polymerized portion that exists outside, the sensitivity is increased as a result without reducing the polymerized area of the original upper and lower quartz plates. It can be maintained.
[0016]
Next, in the invention according to claim 3 of the present invention, the plasma cutting portion of the polymerized quartz plate that has been plasma-cut from one and the other surface side is dissolved by wet etching, and the resonance of this polymerized quartz plate is obtained. 3. The method for producing a quartz crystal plate according to claim 1 or 2, wherein the frequency adjustment is performed, and as described above, in the present invention, the abutting portions of the upper and lower quartz plates protrude outward. In such a state, when dissolving by wet etching and adjusting the resonance frequency, a slight inward dissolution occurs in the abutting portion that can sufficiently protrude outward as described above. Even if this is the case, the sensitivity can be maintained at a high level as a result without reducing the overlap area of the original upper and lower quartz plates.
[0017]
In addition, since the resonance frequency can be adjusted by dissolving by wet etching without worrying about the decrease in the overlapping area of the upper and lower quartz plates in this way, this resonance frequency adjustment is also easier to perform. It becomes.
[0018]
Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
[0019]
FIG. 1 shows an angular velocity sensor used for a car, for example, and this angular velocity sensor 6 has a tuning fork type. The tuning fork type angular velocity sensor 6 is manufactured by following the steps shown in FIGS.
[0020]
Specifically, as shown in FIG. 2, first, the abutting surfaces of the quartz plates 7 and 8 are sufficiently polished, abutting while maintaining a very clean state, and then heated. By this heating, the water present in the contact portion is evaporated, and as a result, an interatomic bond sharing oxygen is performed.
[0021]
Next, as shown in FIG. 3, a gold mask 10 is formed on the front and back sides of the polymerized quartz plate 9 thus polymerized and integrated. Thereafter, although not shown in the drawing, a resin photoresist is formed on the gold mask 10 and patterned into a predetermined shape, and then gold is dissolved in, for example, a potassium iodide solution. Perform patterning. FIG. 4 shows the resin after removing the photoresist. That is, in FIG. 4, the gold mask 10 patterned on the front and back surfaces of the polymerized quartz plate 9 is present.
[0022]
In this state, a nickel mask 11 is provided on the surface of the gold mask 10 as shown in FIG. In this state, as shown in FIG. 6, basically, plasma cutting is first performed from one side, for example, from the upper side shown in FIG. 6, using a gas such as CF4, CHF3, or Ar. Then, plasma cutting is performed using the gas in the same manner from below in FIG. The result is shown in FIG.
[0023]
As shown in FIG. 7, the superposed quartz crystal plate 9 has a so-called drum-like state in which the contact portion protrudes outward. The superposed quartz crystal plate 9 shown in FIG. 7 shows one resonator 6A of the angular velocity sensor 6 shown in FIG. As will be understood from the following, in FIG. 6, the right-side superposed crystal plate 9 corresponds to the resonator 6A in FIG. 1, and the left-side superposed crystal plate 9 in FIG. 6 corresponds to the resonator 6B in FIG. It has become.
[0024]
Now, returning to FIG. 7 and continuing the description, as shown in FIG. 7, the contact portions of the upper and lower crystal plates 7 and 8 are sufficiently protruded outward. In this state, the resonance frequency is adjusted for each of the resonators 6A and 6B shown in FIG. In this case, wet etching is performed on the structure shown in FIG. The result of this wet etching is the state shown in FIG.
[0025]
As shown in FIG. 8, by performing wet etching, the incisions 12 entering inwardly are formed on both sides (outward projecting portions) of the abutting portions of the crystal plates 7 and 8. In FIG. 8, it is clear from the comparison with FIG. 17, but the overlapping area of the upper and lower quartz plates 7 and 8 is not reduced so much. In other words, even if this notch 12 is formed, the overlapping area of the upper and lower quartz plates 7 and 8 can be kept sufficiently large, which leads to an increase in sensitivity.
[0026]
FIG. 9 shows a subsequent state, that is, a state in which the nickel mask 11 is removed from the state of FIG. Accordingly, the gold mask 10 is present on the surfaces of the quartz plates 7 and 8. Although the gold mask 10 can be used as an electrode as it is, for example, in the case of the angular velocity sensor shown in FIG. 1, it is required to attach a gold electrode not only to the front and back surfaces but also to the side surface. . Therefore, in this case, in order to avoid a difference in film thickness from the side electrodes, the gold mask 10 shown in FIG. 9 is also removed, and then the front and back surfaces of the resonators 6A and 6B shown in FIG. An electrode is formed on the side surface. Since the resonator shown in FIG. 1 is conventionally known, further description of this electrode relationship is avoided.
[0027]
Next, FIGS. 10 to 12 show another embodiment of the present invention.
[0028]
That is, FIG. 10 shows that when the plasma cutting is first performed from above as shown in FIG. 6, the gold mask 10 and the nickel mask 11 are also applied to the central portion corresponding to the cutting portion. Will be provided. If the island-shaped masks 10 and 11 are left in the central portion of the plasma cutting portion in this way, and the plasma cutting is performed from above, for example, as shown in FIG. The outside of 11 is dug into a circular groove, for example. The leading end reaches the lower quartz plate 8.
[0029]
In this state, as shown in FIG. 12, when the plasma cutting is performed from below, the hole from which the plasma cutting is performed first reaches the circular groove 13 from above as shown in FIG. As shown in FIG. 12, the state where the upper and lower crystal plates 7 and 8 are in contact with each other protrudes outward, that is, the drum shape is described in the above description. It will be reproduced. As a result, as shown in FIG. 8, the effect can be sufficiently improved with respect to the subsequent wet etching for adjusting the resonance frequency.
[0030]
【Effect of the invention】
As described above, in the present invention, at least two quartz plates are interatomically bonded, the polymerized quartz plate is cut with plasma from one surface side, and then the polymerized plate corresponding to the cut surface from the one side is used. Plasma cutting is performed from the other surface side of the quartz plate, and when the polymerized quartz plate is cut by plasma from one and the other surface side, the cutting is a physical cutting. Unlike the wet etching, the shape change due to the difference in the etching rate of the crystal plane hardly occurs.
[0031]
In other words, when plasma cutting is performed from the front and back surfaces, the contact portions of the superposed quartz plates have shapes that protrude outward, and thus have shapes that protrude outward. Even if the resonance frequency is adjusted by dissolving it by, for example, wet etching after that, it is only in contact with the top and bottom and the part protruding outward is slightly cut inward. In such a case, the original superposed area of the upper and lower quartz plates is not reduced, and this can increase the sensitivity.
[Brief description of the drawings]
FIG. 1 is a perspective view of an angular velocity sensor adopting an embodiment of the present invention. FIG. 2 is a cross-sectional view showing a manufacturing process thereof. FIG. 3 is a cross-sectional view of the same. [Fig. 6] Cross-sectional view [Fig. 7] Cross-sectional view [Fig. 8] Cross-sectional view [Fig. 9] Cross-sectional view [Fig. 10] Cross-sectional view showing another embodiment of the present invention [Fig. Fig. 12 Cross-sectional view Fig. 13 Cross-sectional view showing a conventional example Fig. 14 Cross-sectional view Fig. 15 Cross-sectional view Fig. 16 Cross-sectional view Fig. 17 Cross-sectional view ]
1, 2 Crystal plate 3, 4 Gold mask 5 Polymerized crystal plate 6 Angular velocity sensor 7, 8 Crystal plate 9 Polymerized crystal plate 10 Gold mask 11 Nickel mask 12 Notch

Claims (3)

At least two quartz plates are interatomically bonded, the polymerized quartz plate is cut by plasma from one surface side, and then from the other surface side of the polymerized quartz plate corresponding to the cut surface from one side. A method of manufacturing a quartz polymer plate that performs plasma cutting. An island mask is provided on the cut part of one surface of the polymerized crystal plate, and plasma cutting is performed so that the periphery of the island mask reaches another crystal plate that is superposed on this crystal plate. The method for producing a quartz polymer plate according to claim 1, wherein plasma cutting is performed from the other surface of the quartz plate. The quartz crystal weight according to claim 1 or 2, wherein the plasma cutting portion of the polymerized crystal plate that has been subjected to plasma cutting from one and the other surface side is dissolved by wet etching to adjust the resonance frequency of the polymerized crystal plate. Plywood manufacturing method.

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